Alpha-2 Plasmin Inhibitor, Plasma (A2PI)

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Test Code: A2APSO

Overview
Ordering
Specimen
Performing
Clinical/Interpretive
Contacts
Coding

Synonyms/Keywords

Alpha 2 Plasmin Inhibitor
Antiplasmin
Antiplasmin, Functional, Plasma
Functional Antiplasmin
Plasmin Inhibitor

Useful For

Diagnosing congenital alpha-2 plasmin inhibitor deficiencies (rare)

Providing a more complete assessment of disseminated intravascular coagulation, intravascular coagulation and fibrinolysis, or hyperfibrinolysis (primary fibrinolysis), when measured in conjunction with fibrinogen, fibrin D-dimer, fibrin degradation products, soluble fibrin monomer complex, and plasminogen

Evaluating liver disease

Evaluating the effects of fibrinolytic or antifibrinolytic therapy

Specimen Requirements

Fasting Required	Specimen Type	Preferred Container/Tube	Acceptable Container/Tube	Specimen Volume	Specimen Minimum Volume (allows for 1 repeat)	Pediatric Minimum Volume (no repeat)
No	Platelet-poor Plasma	Citrated Blue Top Tube (BTT)		1.0 mL	0.5 mL

Collection Processing Instructions

1. Spin down, remove plasma, and spin plasma again.
2. Freeze specimen immediately at < or =-40 degrees C, if possible.

Additional Information:
1. Double-centrifuged specimen is critical for accurate results as platelet contamination may cause spurious results.
2. Each coagulation assay requested should have its own vial.

Specimen Stability Information

Specimen Type	Temperature	Time
Citrated Plasma	Frozen	14 days

Rejection Criteria

Gross Hemolyis

Gross Lipemia

Gross Icterus

Interference

Alpha-2 plasmin inhibitor results are potentially affected by:

-Heparin, unfractioned or low-molecular-weight >4 U/mL

-Alpha-2-macroglobulin >7 mg/mL; potentially leading to falsely-increased result

-Hemoglobin >200 mg/dL

-Bilirubin >20 mg/dL

-Triglycerides >1,000 mg/dL

Performing Laboratory Information

Performing Location	Day(s) Test Performed	Analytical Time	Methodology/Instrumentation
Mayo Clinic Laboratories	Monday through Friday	3 to 7 days	Chromogenic

Reference Lab

Mayo Clinic Laboratories

Test Information

Alpha-2 plasmin inhibitor (antiplasmin) is synthesized in the liver with a biological half-life of approximately 3 days. It inactivates plasmin, the primary fibrinolytic enzyme responsible for remodeling the fibrin thrombus, and binds fibrin, together with factor XIIIa, making the clot more difficult to lyse. Absence of alpha-2 plasmin inhibitor results in uncontrolled plasmin-mediated breakdown of the fibrin clot and is associated with increased risk of bleeding.

Reference Range Information

Adults: 80-140%

Normal, full-term and premature infants may have mildly decreased levels (> or =50%) which reach adult levels < or = 90 days postnatal.*

Interpretation

Patients with congenital homozygous deficiency (with levels of <10%) are clinically affected (bleeding). Heterozygotes having levels of 30% to 60% of mean normal activity are usually asymptomatic.

Lower than normal levels may be suggestive of consumption due to activation of plasminogen and its inhibition by alpha-2 plasmin inhibitor.

The clinical significance of high levels of alpha-2 plasmin inhibitor is unknown.

Outreach CPTs

CPT	Modifier (if needed)	Quantity	Description	Comments
85410